Direct motor drive for disk fans



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A. O. HURXTHAL DIRECT MOTOR DRHE FOR DISK FANS b e F d e l F 1 a n i g 1 r 0 Reissued Mar. 9,193:

DIRECT MOTOR DRIVE FOB DISK FANS Al'pheus 0. Hurxthal, Philadelphia, Pa., assig'nor to Proctor & Schwartz, Incorporated, Philadelphia, Pa., a corporation of Pennsylvania Original No. 2,050,180,

dated A 4, 19

Serial No. 713,216, February 27, 1934. Application for reissue October 26, 1936, Serial No.

14 Claim.

This invention relates to power units for driving air-circulating fans of drying machines; and particularly to a unit comprising a direct motor drive for a fan of the disk type.

In connection with the manufacture and operation of driers and similar apparatus requiring the use of a fan for circulating a conditioning or treating medium in a substantially .closed chamber, the disk typefan is used to a considerable extent. l

Since in'this type of fan the air or other medium being circulated thereby'is drawn into and through the fan from one side thereof and ,discharged'i'rom-the fan at the opposite side thereof, it is evident that space must be provided at both sides of the fan to permit it to operate efliciently. v

In order to space the fan inwardly from the walls of the chamber to permit circulation of the 0 medium as above noted and in order to eil'ect rotation of the fan at speeds necessary to provide emcient circulation of the'medlum in the chamber it is necessary to employ a shaft extending into the chamber from at least one wall thereof. I

In order to support the shaft and fan for rotation at the required speeds a bearing for the shaft must be placed adjacent the fan, inside the chamber, and another bearing must be placed near the point on the shaft at which power is applied to the shaft. Usually, as in the case of belt-driven fans, this second bearing is placed outside the chamber or immediately adjacent the wall, either inside or outside thereof, through which the shaft extends. The driving pulley in each instance is placed outside the outer hearing.

In many instances, such for example as where high velocity circulation is required, it is desirable to connect the fan shaft direct to a motor 0 shaft. The motor may be of any desired kind, for example a steam or air turbine-but preferably an electric motor of a suitable type according to th nature of the current available.

This form of drive has met with favor but as practiced has some troublesome characteristic;- For example, it is not practical to extend the motor shaft sufliciently from one side of the motor to provide the air space between the one side of 50 .the fan and the wall which carries the motor as such necessitates the use of a long overhang in the shaft between the fan and the nearest supp n a in In order to overcome this objection in some 55 instances the motor has been set in a cavity in is objectionable for the'reasons that despite pre-,

cautions the motor heats up excessively, lubrica tion of the motor bearings is diflicult and the presence of the full diameter of the motor so close to .the fan-reduces the efliciency of the latter.

In most instances, however, the motor has been maintained outside the chamber and a supplemental fan shaft has been aligned with and coupled to the rotor shaft of themotor and supported by a supplemental bearing located inside the chamber-adjacent the fan.

Driers and other processing and treating appa'ratus which are usually constructed of light structural steel having no true machined surfaces and subject to considerable expansion, contraction and more or less warping, as a result of temperature conditions, makes it practically impossible .to effect and maintain true alignment between the three bearings which support the rotor and supplemental shafts, i. e. the two motor bearings and the supplemental bearing. consequently this dual fan shaft and the coupling be-- tween the two sections thereof'is placed under lateral as well as torque strains, causing trouble in the coupling; and the bearings, due to such lateral strains, heat up and wear excessively.

The object of the present invention is to provide a direct motor drive for fans which obviates each and all the above noted disadvantages of the structures of the prior art and at the same time incorporates all the desirable, features attending the use of this form of drive.

The construction and operation oi the unit forming .the subject matter of the present invention will be fully disclosed hereinafter,

reference being had to the accompanying drawing, of which:

Fig. 1 is a longitudinal sectional elevation of the unit; and

Fig. 2 diagrammatically illustrates the unit as applied to a drier of any desired type, the drier being shown in sectional elevation;

'As shown in Fig. 2, a drier or other treating or processing apparatus usually comprises a structural framework I covered with sheet metal or other sheathing 2 which in many instances is of a double wall construction filled with a suit- -able heat-insulating material. Frequently the walls of the apparatus are made up of panels which are secured to and readily removable from the structural framework l. I

In anyvevent the walls 2 enclose and form a chamber 3 in which material isplaced for treatment, and a chamber I in which are disposed steam or other heating or medium conditioning pipes 5.

The chamber I is separated from the chamber 3 by a partition 6 in which is formed a circular opening 1 for the fan ill, which by rotation within the opening I causes a circulation of air or other medium through the opening 6, from the chamber 3 into the chamber I and through i this latter chamber and returning to the first structure and adapted to be secured to the frametion to the opposite end of the rotor 2|, in th work as by bolts ll with one portion la extend- I ing through an opening it into the chamber I and another portion l5b disposed outside the casing formed by the walls 2.

According to the principles of the present invention, the bearing I2 is formed on or carried by the innermost end of the portion lid of the rigid structure l5 and is disposed immediately adjacent the fan I0, while the bearing i3 is formed in or carried by the outermost end of the structure l5 in a third section |5c thereof,

which is rigidly secured to thesection lib of said structure.

The section |5b in the present instance constitutes the main or body portion of an electric motor of any suitable type and houses the stator 25 within which the rotor 2| secured to the shaft I, is adapted to rotate and consequently eflect rotation of the shaft ll.

The section |5c constitutes one removable end or bonnet oi the motor housing; and the section |5a constitutes the opposite end or bonnet of the motor housing. However, the bonnet lid in the present instance is elongated to a considerable extent from the usual motor construction to provide the bearing l2 remotely situated with respect to one end or the rotor 2|, instead of being in close adjacent relation to therotor as is usual in electric motors, while the section l5c provides the bearing l3 disposed in close adjacent relausual manner. h

It is common practice in motor construction to ventilate the motor by circulating air from one end of the motor housing through openings formed in the one bonnet at that end of the motor and through openings formed in or surrounding the stator in the main section of the the inner end of the rotor 2|, said air being exhausted through openings 26, formed in the .motor section l5b, by centrirugal action set up by a set of blades 21 formed on one side of a disk 23 which constitutes the body of the fan and extends circularly and radially from the hub 23 of the fan on the shaft II.

In the present instance the Ian 25 is of a double construction and comprises a second set of blades 30 formed on the opposite side of the disk 28 from the blades 21.

In the lower portion of and extending longitudinally along the lower portion of the elongated bonnet l5a, in the present instance, is an air duct 3| which has an opening or port 32 outside the flange l6 which establishes communication between the duct 3| and the atmosphere outside the drier casing.

At its opposite end the duct 3| communicates with the interior of the elongated bonnet I50 through an opening or port 33 disposed immediately adjacent the inner bearing l2, for keeping said bearing cool.

Circulation of air in one direction in the bonnet l5a, through the duct 3|, around the bearing 2, in an opposite direction through the interior or the bonnet Ho, and outwardly through the exhaust ports 25 is created by the centrifugal action of the blades 35 of the tan, pump or impeller 25.

The disk 23 ot the impeller 25 constitutes a baiiie between the interior of the elongated hood or bonnet section l5a of the rigid structure 15 and the interior of the motor housing sections I54 and I50 01 said structure and thereby prevents the air which becomes heated by radiation from the interior of the chamber I to the interior of the bonnet l5a. through the metal wall of said bonnet, from passing into the motor housing, thut:d the impeller serves the dual, purpose above no The bearing I2 is lubricated, in .the present instance by means of a tube 3I having one end communicating with a passage 35 formed in the innermost end wall of the bonnet |5a which leads the lubricant to, in the present case, the ball races of a ball bearing suitably mounted in the said end wall or said bonnet. The opposite end of the tube 35 communicates with a grease or oil cup or a pressure fitting disposed outside the rigid housing or unit l5.

The tube 3I being wholly within the bonnet |5o in the pathof the cooling air circulated through the interior of the bonnet |5a by the impeller 25 maintains the lubricant in the tube at a temperature which prevents its losing viscosity and value as a lubricant in the bearing l2.

The outer bearing l3 for the shaft is supplied with lubricant from and through a suitable oil or grease cup or pressure fitting 31 disposed outside the shallow bonnet |5c of the unit l5.

From the above, it will be apparent that due to the rigidity of the structure l5 the two sole bearings for the shaft II are at all times held in strict axial alignment, regardless of expansion and contraction or other distortion of the framework I upon which the rigid structure I5 is mounted and to which it is secured at and in a single transverse plane intermediate said bearings; that the shaft II is supported firmly adjacent the fan Ill; and that the inner bearing is cooled and lubricatedeiflciently despite its location well within the heated chamber of the apparatus in whichthe unit is installed.

I claim:

1. A direct motor drive unit comprising a rigid elongated unitary hollow housing, means extending transversely of and from the housing intermediate its opposite ends for solely supporting the unit, a one piece shaft extending longithe opposite end of the housing between the plane of the supporting means and the second of said bearings with the rotor of said motor mounted directly on said shaft, and the portion of the housing between the housing-supporting means and said driven means tapering toward said driven means.

2. A direct motor drive unit comprising a rigid elongated unitary hollow housing, means extending transversely of and from the housing intermediate its opposite ends for solely supporting the unit, a one piece shaft extending longitudinally through and beyond one'end of the housing, a

pair of bearings respectively disposed at the opposite ends of the housing and affording the sole means of support for the shaft, driven means secured to the projecting end of the shaft adjacent one of said bearings, a motor in the opposite end of the housing between the plane of the supporting means and the second of said bearings with the rotor of said motor mounted directly on said shaft, and the portion of the housing between the housing-supporting means and said driven means tapering toward said driven means, a baflie'encircling the shaft between the motor and the tapering end of the housing, and means for drawing cooling air into the tapering end of the housing and circulating said air around the shaft bearing therein and exhausting said air from the housing adjacent the baflie.

3. A direct motor drive unit comprising a rigid elongated unitary hollow housing, means extending transversely of and from the housing intermediate its opposite ends for solely supporting the unit, a one piece shaft extending longitudinally through and beyond one end of the housing, a pair of bearings respectively disposed at the opposite ends of the housing and affording the sole means of support for the shaft, driven means secured to the projecting end of the shaft adjacent one of said bearings, a motor in the opposite end of the housing between the plane of the supporting means and the second of said bearings with the rotor of said motor mounted directly on said shaft, and the portion of the housing between the housing-supporting means and said driven means tapering toward said driven means, a baflie disk secured to the shaft intermediate the motor and the tapering end of the housing, and impeller blades on the baflie diskfor drawing cooling air through the tapering end of the housing and around the shaft bearing therein, said housing being provided with exhaust ports adjacent the periphery of said baflie disk.

4. A direct motor drive unit comprising a rigid elongated unitary hollow housing, means extending transversely of and from the housing intermediate its opposite ends for solely supporting the unit, a one piece shaft extending longitudinally through and beyond one end of the housing, a pair of bearings respectively disposed at the opposite ends of the housing and affording the sole means of support for the shaft, driven means secured to the projecting end of the shaft adjacent one of said bearings, amotor in the ports adjacent the directly on said shaft, and the portion of the housing between the housing-supporting means and said driven means tapering toward said driven means, a baflie disk secured to the shaft intermediate, the motor and the tapering end of the housingfand impeller blades on the opposite sides respectively of said baflie disk for drawing cooling air through the tapering end of the housing and around the shaft bearing therein at one side of the baifle disk and through the motor at the opposite side of the baflie disk, said housing being provided with exhaust ports adjacent the periphery of the housing.

5. A direct motor drive unit comprising a rigid elongated unitary hollow housing, means extending transversely of and from the housing intermediate its opposite ends for solely supporting the unit, a one piece shaft extending longitudinally through and beyond one end of the housing, a pair of bearings respectively disposed at the opposite ends of the housing and affording the sole means of support for the shaft, driven means secured to the projecting end of the shaft ,adjacent one of said bearings, a motor in the opposite end of the housing'between the plane of the supporting means and the second of said bearings with the rotor of said motor mounted directly on said shaft, and the portion of the housing between the housing-supporting means and said driven means tapering toward said driven means, a bailledisk secured to the shaft intermediate the motor and the tapering end of the housing, impeller blades on the baflie disk for drawing cooling air through the tapering end of the housing and around the shaft bearing therein, said housing being provided with exhaust periphery of said bailie disk, and means for lubricating the bearing adjacent the end of the housing at which said driven means is-located and including a fitting disposed in the motor end of the housing adjacent the plane of the unit-supporting means and a tube leading from said fitting to said bearing and extending through the tapering end of the housing in the path of the cooling air passing therethrough.

6. A direct motor drive unit comprising a rigid elongated unitary hollow housing, means extending transversely of and from the housing intermediate its opposite ends for solely supporting the unit, a one piece shaft extending longitudinally through and beyond one end of the housing, a

pair of bearings respectively disposed at the opposite ends of the housing and afl'ording the sole means of support for the shaft, driven means secured to the projecting end of the shaft adjacent one of said bearings, a motor in the opposite end of the housing between the plane of the supporting means and the second of said bearings with the rotor of said motor mounted cylindrical section, a .shallow bonnet secured to one end of the cylindrical section, and a relatively long tapering bonnet secured to the opin the outer end of each of said bonnets aflording the sole means of support for said shaft, an

annular flange on the long tapering bonnet adjacent the cylindrical section and affording the sole means of support for the unit, driven means secured to the shaft adjacent the bearing in the long tapering bonnet, an air duct having an inlet adjacent said flange and an outlet adjacent the bearing in the tapered end of said long bonnet, a baffle disk on the shaft between the motor and the long bonnet, impeller blades on the opposite sides of said baflle disk for drawing cooling air through said duct and around the bearing in the long tapered bonnet and through openings in said shallow bonnet and said motor and discharging said air through exhaust'ports formed in the cylindrical section adjacent the periphery of said bailie disk, and means for lubricating the bearing in the long bonnet comprising a fitting adjacent said annular flange and a tube leading from said fitting to said bearing in the path of the air circulating through said long bonnet.

.8. A direct motor drive unit comprising a rigid elongated unitary hollow housing, means extending transversely of and from the housing intermediate its opposite ends for solely supporting the unit, a one piece shaft extending longitudinally through and beyond one end of the housing, a pair of bearings respectively disposed at the opposite ends of the housing and affording the sole means of support for the shaft, driven means secured to the projecting end of the shaft adjacent one of said bearings, and a motor in the opposite end of the housing between the plane .of the supporting means and the second of said bearings with the rotor of said motor mounted directly on said shaft.

9. A direct motor drive unit comprising a rigid elongated unitary hollow housing, means extending transversely of and from the housing intermediate its opposite ends for solely supportting the unit, a one piece shaft extending longitudinally through and beyond one end of the housing, a pair of bearings respectively disposed at theopposite ends of the housing and aifording the sole means of support for the shaft, driven means secured to the projecting end of the shaft adjacent one of said bearings, a motor in the opposite end of the housing between the plane of the supporting means and-the second of said bearings with the rotor of said motor mounted directly on said shaft, a batlie encircling the shaft between the motor and the end of the housing adjacent which said driven means is disposed. and means for. drawing cooling air into the last said end of thehousing and circulating said air around the shaft-bearing therein and exhausting said air from the housing adjacent the baiiie.

10. A direct motor drive unit'comprisinga rigid elongated unitary. hollow housing, means extending transversely of and from the housing intermediate its opposite ends for solely supporting the unit, a one piece shaft extending longitudinally through and beyond one end of the housing, a pair of bearings respectively disposed at the opposite ends of=the housing and affording the sole means of support for the shaft, driven means secured to the projecting d of the shaft adjacent one of said bearings, a motor in the opposite endof the housing between the plane of the supporting means and the second of said bearings with the rotor of said metor mounted directly on said shaft, 8. bailie disk secured to the shaft intermediate the motor and the end of the housing adjacent which said driven means is disposed, and impeller blades on the baiiie disk for drawing cooling air through the last said end of the housing and around the shaft bearing therein, said-housing being provided with exhaust ports adjacent the periphery of said bafiie disk.

11. A direct motor drive unit comprising a rigid elongated unitary hollow housing, means extend-,

i jace'nt one of said bearings, a motor in the opposite end of the housing between the plane of the supporting means and the second of said bearings with the rotor of said motor mounted directly on said shaft, a baille disk secured to the shaft intermediate the motor and the last said end of the housing, and impeller blades on the opposite sides respectively of said baflie disk for drawing cooling air through the last said end of the housing and around the shaft bearing therein at one side of the baflle disk and through the motor at the opposite side of the baflle disk, said housing being provided with exhaust ports adjacent the periphery of the housing.

. 12. A direct motor drive unit comprising a, rigid elongated unitary hollow housing, means ex tending transversely of and from the housing intermediate its opposite ends for solely supporting the unit, a one piece shaft extending longitudinally through and beyond one end of the housing, a pair of bearings respectively disposed at the opposite ends of the housing and affording the sole means of support for the shaft, driven means secured to the projecting end of the shaft adjacent one of said bearings, a motor in the opposite end of the housing between the plane of the supporting means and the second of said bearings with the rotor of said motor mounted directly on said shaft, a baiiie disk secured to the shaft intermediate the motor and the last said end of the housing, impeller blades on the baflle disk for drawing cooling air through the last said end of the housing and around the shaft bearing therein, said housing being provided with exhaust ports adjacent the periphery of said baflle disk, and means for lubricating the bearing adjacent the end of the housing at which said driven means is located and including a fitting disposed in the motor end of the housing adjacent the plane of the unit-supporting means and a tube leading from said fitting to said bearing and extending through the end of the housing at ,which the driven means is located in the path of the cooling air passing therethrough.

13. A direct motor drive unit comprising a rigid elongated unitary hollow housing, means extending transversely of and from the housing intermediate its opposite ends for solely supporting the unit, a one piece shaft extending longitudinally through and beyond one end of the housing, a pairof bearings respectively disposed at the opposite ends of the housing and afl'ordin'g'the sole means of support for the shaft, driven means secured to the projecting end of the shaft adjacent-one of said bearings, a motor in the opposite end. oi the housing between the planeof the supporting means and the second 0! said bearings with the rotor of said motor mounted directly on said shaft, an air duct formed in the end of the housing at which the driven means is located with an inlet communicating with the atmosphere adjacent the unit-supporting means and an outlet communicating with the interior of the housing adjacent the shaft bearing in the end of the housing at which the driven meansis located, and an impeller on the shaft for drawing air through the duct and around said shaft bearing.

14. A direct motor drive unit comprising a rigid elongated unitary hollow housing composed oi a cylindrical section, a shallow bonnet secured to one end of the cylindrical section, and a relatively long bonnet secured to the opposite end of said cylindrical section. a motor stator and a motor rotor mounted in said cylindrical section, a shaft extending-through said cylindrical section and said bonnets, and to which the motor stator is directly secured, a bearing in the outer end of each of said bonnets aflording the sole means 01 support for said shaft, an annular flange on the long bonnet adjacent the cylindrical section and afl'ording the sole means of support for the unit, driven means secured to the shaft adjacent the bearing in the long bonnet, an air duct having an inlet adjacent said flange and an outlet ad"v jacent the bearing in the end of said long bonnet, a baflle disk on the shaft between the motor and the long bonnet, impeller blades on the opposite sides' of said baflledisk for drawing cooling air through said duct and around the bearing in the long bonnet and through openings in said shallow bonnet and said motor and discharging said air through exhaust ports formed in the cylindrical section adjacent the periphery of said baiile disk, and means for lubricating the bearing in the long bonnet comprising a fitting adjacent said annular flange and a tube leading irom said fitting to said bearing in the path of the air circulating through said long bonnet.

ALPHEUS O. HURXTHAL. 

